To be honest there are so many factors that influence your decisions as to what is the best.
1) What is your primary use for a pc (gaming, work, movies etc)
2) Do you have access to the internet, if so, are you permanently connected?
3) Do other individuals utilise your machine?
4)Do you constantly receive all your information (ie: music, documents, movies etc) from other individuals, or do you download / create the aforementioned examples yourself?
5)Do you utilise original software or pirated software?
6)Are you linked to a VPN, LAN with other users connected?
There are so many variables to consider in deciding which is the best. Everyone has a different use therefore I just say if it does the job for you then use it. If you are working in a hostile environment (as in access to some potentially hectic worms, trojans, viruses and spyware) then you are going to require bigger guns to fight the battle.